This proposal has three parts. The first is concerned with production of inhibitors or "chalones", both in an animal model and in humans with anergic diseases. Our data thus far would suggest that there are humoral inhibitors of delayed hypersensitivity and we are presently surveying and isolating such inhibitors. The second portion of this grant is concerned with the cell receptor of delayed hypersensitivity and we are currently preparing reagents to study that portion of the sheep red cell surface which is concerned with the T-lymphocyte receptor. The third component of our studies involves the biologic role of macrophage cytophilic antibody and includes the newly described area of cutaneous basophil hypersensitivity. In this study the transfer of this hypersensitivity has been affected by antibody and we are currently isolating the antibody to determine by what mediators basophils are attracted to the reaction site.